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America's Climate Choices (2011) / Chapter Skim
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5 Key Elements of America's Climate Choices
Pages 51-80

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From page 51...
... LIMITING THE MAGNITUDE OF CLIMATE CHANGE Limiting the magnitude of climate change requires stabilizing atmospheric greenhouse gas (GHG) concentrations, which in turn requires reducing emissions of these gases so that their emissions are no greater than the rate at which they are naturally removed from the atmosphere.
From page 52...
... Here we provide a very brief overview, starting with the more general issue of setting goals for limiting the magnitude of climate change. BOX 5.1 Geoengineering Geoengineering, applied to climate change, refers to deliberate, large-scale manipulations of the Earth's environment intended to offset some of the harmful consequences of GHG emissions, and it encompasses two very different types of strategies: solar radiation management and post-emission GHG management.a Many proposed geoengineering approaches are ambitious concepts with global environmental consequences; as such, they have attracted a great deal of attention.
From page 53...
... More fundamentally, intentional alteration of the Earth's environment via geoengineering raises significant ethical issues, including the distribution of risks among population groups in both present and future generations, as well as challenging questions of public perceptions and acceptability.f In conclusion, geoengineering approaches may conceivably have a role to play in future climate risk management strategies, particularly if efforts to reduce global GHG emissions are unsuccessful or if the impacts of climate change are unexpectedly severe. At present however, the costs, benefits, and risks of many geoengineering approaches are not well understood.
From page 54...
... For any given global temperature goal, corresponding goals can then be derived for atmospheric GHG concentrations that would give a reasonable chance of meeting the temperature goal, for global GHG emissions limits that would give a reasonable chance of meeting those GHG concentration goals, and, finally, for national GHG emission limits that would collectively achieve the needed global emission reductions. These relationships are complicated, however, by a variety of scientific uncertainties and value judgments (see Figure 5.1)
From page 55...
... FIGURE 5.1 A schematic illustration of the steps involved in setting goals for limiting the magnitude of future climate change, and some key questions and uncertainties that need to be considered in each of these steps. Reducing Global Emissions The United States currently accounts for roughly 20 percent of global CO2 emissions, despite having less than 5 percent of the world's population.
From page 56...
... This is primarily because reducing global GHG emissions requires limiting the growth in emissions from developing countries. Additional motivation comes from the fact that it is generally less expensive to reduce emissions in developing nations than in developed ones (although the evidence can vary considerably depending on the specific context)
From page 57...
... But federal, state, and local governments have a large role to play in influencing these key stakeholders through effective policies and incentives. In general, there are four major tool chests from which to select policies for driving GHG emission reductions: • pricing of emissions by means of a tax or cap-and-trade system; • mandates or regulations, which includes full-scale programs of controls on emitters (for example through the Clean Air Act)
From page 58...
... Estimating possible future carbon prices, which depends on many unpredictable factors, such as the pace of technology development, is beyond the scope of this study; but NRC, Limiting the Magnitude does contain a detailed discussion of future carbon price projections made in the recent multi-model studies of the Energy Modeling Forum.12 In addition to a price on carbon, there is a need for complementary policy measures that help to overcome market failures not fully addressed by a carbon price.13 Complementary policies may also be needed to overcome institutional barriers that inhibit responses to carbon prices and/or slow the penetration of new low-carbon technologies.14 Examples of such barriers include outdated building codes and regulatory systems15 and the information-related problems that reduce incentives for builders and home owners to invest in energy-efficient homes and appliances.16 Complementary policies must be chosen strategically, however -- an optimal policy reduces emissions where it is cheapest to do so, not taking all possible measures, nor requiring all sectors 58
From page 59...
... These rules, if adopted, 18 will likely achieve emission reductions and may also stimulate innovation, but the regulatory strategy is not as likely as a well-crafted pricing strategy to provide continuous incentives to find the cheapest path to significant GHG reductions.19 RECOMMENDATION 1: In order to minimize the risks of climate change and its adverse impacts, the nation should reduce greenhouse gas emissions substantially over the coming decades. The exact magnitude and speed of emissions reduction depends on societal judgments about how much risk is acceptable.
From page 60...
... In addition, strategically-targeted complementary policies are needed to ensure progress in key areas of opportunity where market failures and institutional barriers can limit the effectiveness of a carbon pricing system. If a pricing strategy proves to be politically infeasible, second-best approaches may include the expansion of regional, state, and local initiatives already under way, along with the adoption of national-level mandates or performance standards, some of which could potentially be implemented through the Clean Air Act.
From page 61...
... . Finally, as with all elements of an iterative risk management strategy, actions taken to reduce GHG emissions need to be carefully monitored.
From page 62...
... Thus, just as the committee recommends that America embark on a course of substantial emission reductions, we recommend that America take proactive actions to mobilize the nation's capacity to adapt to future climate changes. This dual-path strategy will reduce the risks of future climate-related damages more than pursuing either path alone.
From page 63...
... An Effective National Adaptation Strategy Much of the work of adaptation will be done by state, local, and tribal21 governments, private-sector firms, nongovernmental organizations, and representatives of especially vulnerable regions, sectors, or groups. Decision makers at these levels often lack the resources necessary to perform this work effectively or lack experience in accessing and using information that may be available to inform their decisions.
From page 64...
... Yet another important component of a national adaptation strategy is to evaluate existing 64
From page 65...
... Recent estimates suggest a reduction of roughly 6 percent for each degree of increase in global mean temperature over the coming century or beyond.d The southwest region has long struggled with issues of water availability as population has grown,e and the challenges of coping with scarce water resources in this region will only be exacerbated by declines in future water availability due to climate change. A study of potential climate change impacts on the Colorado River system (a system that roughly 30 million people depend upon for drinking and irrigation water)
From page 66...
... Accordingly, federal efforts need to include not just formulating an initial national adaptation strategy but also creating durable institutions (or in some cases, strengthening existing institutions) that can revise and improve that strategy over time, in light of new knowledge and new policy options.
From page 67...
... Together with research that enhances fundamental understanding of the climate system, there is a need for research that generates additional options for limiting climate change and adapting to its impacts, and research on how to effectively inform decision making through decision support tools and practices. For example, the development of new technologies for reducing GHG emissions should be accompanied by studies aimed at understanding barriers to their implementation.
From page 68...
... Just as it is appropriate for the federal government to support research on earthquake-resistant building codes (that can be applied by many local governments, none of which could afford the cost of such research alone) , so it is appropriate for the federal government to support research on standards for the design of roads, bridges, and other structures that will perform well under a variety of possible future climates.
From page 69...
... NRC, Informing Effective Decisions identifies several key aspects of information support to help decision makers develop effective responses to climate change, including the following: • Information on climate change, vulnerability, and impacts in different regions and sectors is needed for formulating adaptation strategies and understand ing how GHG emissions reductions may reduce risks. • Institutions and mechanisms for "climate services" (i.e., the timely production and delivery of useful climate data, information, and knowledge to decision makers)
From page 70...
... • Public communication must rest on high quality information that clearly conveys climate science and climate choices and that is seen as coming from trusted sources. • Because many climate-related choices are occurring in an international context (e.g., in the case of global agricultural and trade systems)
From page 71...
... Such efforts are clearly valuable in national debates about whether climate change is happening, and whether responses are effective. RECOMMENDATION 4: The federal government should lead in developing, supporting, and coordinating the information systems needed to inform and evaluate America's climate choices, to ensure legitimacy and access to climate services, greenhouse gas accounting systems, and educational information.
From page 72...
... INTERNATIONAL ENGAGEMENT The United States has a strong national interest in ensuring an effective global response to climate change, because if domestic GHG emissions reductions are to be effective in actually limiting climate change, they must be accompanied by significant emission reductions from all major emitting countries. Also, the United States can be deeply affected by climate change impacts occurring elsewhere, given the degree to which different nations are linked by shared natural resources (e.g., fisheries, crossborder river systems)
From page 73...
... In 2010, the NRC assessed existing capabilities for estimating and verifying GHG emissions and identified ways to improve these capabilities through strategic near-term investments.27 The United States also has much to gain from actively participating in international adaptation efforts, particularly those involving developing nations. It is in the nation's interest to limit the potentially destabilizing impacts of climate change in the developing world, and it can be argued that our large contribution to current and historic global GHG emissions gives us some responsibility to assist those whose vulnerabilities exceed their resources.
From page 74...
... leadership could well prove critical. Carefully targeted and coordinated R&D efforts can help enable developing nations to achieve both the economic growth necessary to alleviate poverty and the GHG emissions reductions necessary to limit future climate change.
From page 75...
... Informing Effective options Effective options Science may be for limiting climate for adapting to more attuned to change may be climate change decision needs, more widely may be more and public support deployed and widely deployed for advances in used. and used.
From page 76...
... The federal government can play an important leadership role by providing widely useful knowledge and information, but an effective national adaptation strategy will be based not on top-down federal directives. Rather, it will be based on coordination and information sharing across levels of government and between public and private sectors.
From page 77...
... Moreover, even the USGCRP and the Climate Change Technology Program together do not appear sufficient for effectively coordinating the full portfolio of research needed to support climate change response efforts. One can look to other major policy arenas (e.g., public health, national security)
From page 78...
... In summary, the following are some essential coordination challenges that a national climate change response effort will need to address: • Ensuring that federal actions facilitate (or at a minimum, do not impede) effec tive nonfederal actions for mitigation and adaptation; • Developing a clear division of labor among federal agencies and a process to monitor how well this division of labor is functioning over time; • Ensuring decision support for constituencies that do not have a particular government agency or program responsible for providing such information; and • Linking science, decision support, and resource management functions within the federal response to climate change.
From page 79...
... America's climate choices will involve political and value judgments by decision makers at all levels. These choices, however, must be informed by sound scientific analyses.


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